1. Field of the Invention
This invention relates generally to a torsion spring suspension for use on a motor vehicle. More particularly, the present invention relates to a torsion spring adjustment apparatus for retaining a torsion spring in a predetermined orientation and preload.
2. Disclosure Information
Torsion spring suspensions are well known in the motor vehicle industry. The design is desirable for its ability to provide simplified, low cost ride height adjustments to compensate for vehicle build tolerances and weight variations of vehicles having different customer preferred options.
One problem associated with torsion spring suspensions relates to dynamic reaction loads imposed on the vehicle structure at the spring adjuster seat. To minimize the stresses throughout the suspension components when subjected to these dynamic reaction loads the torsion spring should not be rigidly attached to the chassis. One solution is to provide a floating adjuster for securing the torsion spring to the vehicle structure. Thus, a floating torsion spring adjuster must maintain a predetermined angular orientation, which in turn maintains a predetermined preload in the torsion spring, while allowing the torsion spring to undergo very small lateral and longitudinal displacement in response to various suspension movements, including recession, jounce and rebound. While this effectively reduces stresses within the suspension components, the looseness of the adjuster may result in the generation of objectionable operational noises. One of these objectionable noises is best described as a clunk. Conventional elastomeric isolators have been unsatisfactory as they typically do not last long when subjected to the dynamic reaction loads imposed by the torsion spring.
It would be desirable to provide a torsion spring adjuster that minimizes the stresses in the suspension components by using a floating adjuster at the vehicle structure while preventing the generation of objectionable noises, such as clunk.